I had an issue running Perl in Cygwin. I could install the modules I needed, but was unable to compile Term::ReadKey due to sgtty or some other challenges. I kept getting annoying messages around perl like this with “sgtty not found” and it seems to be an eternal issue. I found bug reports back to 2000!
I tried many different tactics within perl, but nothing worked. Turns out, there is a cygwin package you can install directly for this issue. You can run the setup.exe or setup64.exe for cygwin and select the
package to get the module going in perl under cygwin. You are also better-off long term on getting apt-cyg going in the cygwin environment to query and install packages easily in the environment and without the need to fire-up the setup.exe app each time you want to install a package.